1. Field of the Invention
The present invention relates to a near-field antenna measurement system, and more particularly, to an automatic positioning method and apparatus for near-field antenna measurement.
2. Description of the Related Art
In order to align an antenna under test (AUT) and a measurement probe, the AUT radiates the radio frequency (RF) signal, and the measurement probe concurrently measures vertically and horizontally polarized waves of the RF signal, and the AUT and the measurement probe are optionally aligned through the measurement signal processing. If a signal to noise ratio (SNR) of the RF signal measured by the AUT and the measurement probe is low, an error occurs in a process of measuring a signal. Thus, accuracy of alignment of the AUT and the measurement probe is deteriorated. In addition, in case of an antenna in which a main beam of the AUT is polarized in a predetermined direction, the AUT and the measurement probe are aligned by searching for the maximum value of a signal. Accordingly, it is difficult to measure a deflection degree of the main beam through near-field measurement.
In order to align microwave antennas at several or tens of kilometers, an intensive laser beam is transmitted and received. A laser transmission device and a laser sensing device are mounted on an individual antenna. Antennas are aligned by using information on whether the laser beam is received. Accordingly, it is possible to obtain desired accuracy only when the laser transmission device and the laser sensing device are mounted on an accurate position of the antenna at an accurate position and an accurate angle. When the laser transmission device and the laser sensing device are attached or detached, alignment of the antennas is distorted. In addition, the size of the antennas has to be increased so that the laser transmission device and the laser sensing device are mounted on the antennas.